To get a longer life out of your engine use proper oil type, change oil at proper times, and limit stop and go driving.  To know how often the oil needs to be changed look at the owner’s manual.  Many may not know that some driving is harder on a vehicle than other.  Some of the situations to avoid are making frequent short trips (less than five miles), driving in stop-and-go traffic during hot weather, driving at low speeds for long period of times, and driving at sustained high speeds during hot weather. All these conditions can cause engines to become severely overloaded and develop very high engine and oil temperatures, resulting in viscosity breakdown and ultimately engine damage.  No one can avoid these situations all of the time, so that is why oil must be changed regularly.  There are three types of oil: Natural, which is conventional refined crude oil, with additives;  Synthetic, this is a man made oil that can protect engines at more extreme temperatures; and  Synthetic/Natural Blends, a combination of the two, that offers the best of both types.

What do all of the numbers and abbreviations stand for on an oil can? API stands for the American Petroleum Institute, which provides the standards that high quality oils must meet. SL is for all automotive engines presently in use. SL oils are designed to provide better high temperature deposit control and lower oil consumption. SJ is for 2001 and older automotive engines. CF-2 is formulated for use in two-stroke diesel engines requiring highly effective control over cylinder and ring-face scuffing and deposits.
CF-4 covers oils for use in high-speed, four-stroke diesel engines. They are designed for use in on-highway heavy-duty truck applications.  CG-4 describes oils for use in high-speed, four-stroke diesel engines, and is suitable for both highway and off-road applications. They provide effective control of high temperature piston deposits, wear, corrosion, foaming, and oxidation stability and soot accumulation.  SAE stands for Society of Automotive Engineers. Motor oils have SAE grades, or numbers that indicate viscosity. In other words, the SAE numbers tell you the "thickness" of the oil: the lower the number, the "thinner" the oil.  W signifies its winter rating, showing that it will perform well in particularly cold weather.  A viscosity rating of 5W-30 means the winter flow weight of the oil. Colder temperatures tend to thicken oil so that it flows very slowly. This is disastrous to your car's engine. Therefore, in mixing the oil, the refinery adds a chemical that adjusts and stabilizes the oil at the lighter weight when it gets cold outside.

Another reason it is important to use the right type of oil is that if the vehicle breaks down and is still under warranty, but the wrong type of oil was in the engine, the warranty may be voided.  Manufacturers will indicate which type of oil your vehicle should use, and if there are any questions about oil type always ask your mechanic.